Alert archive / North Dakota / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 246, NWS Grand Forks, ND

September 25, 1998Cass County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Sep 25, 1998, 10:30 PM CDT for Cass County, North Dakota. It was in force for 30 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Sep 25, 1998, 10:30 PM CDT (03:30 UTC)
Expired
Sep 25, 1998, 11:00 PM CDT
In force
30 min
Issued by
NWS Grand Forks, ND
Area
Whole counties

County Cass County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 66 km from the middle of the area, began a volume at 03:33 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Sep 25, 10:30 PM CDTHail 0.75Leonard, ND

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 3.5 hours before the alert went out and 243 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 1998-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 1998-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 189 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2176 m above ground
0-6 km bulk shear
76 kt
0-1 km storm-relative helicity
189 m²/s²
0-3 km storm-relative helicity
415 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

675 
WUUS1 KFAR 260332 RRA
SVRFAR
NDC017-260405-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1030 PM CDT FRI SEP 25 1998

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN CASS COUNTY IN SOUTHEASTERN NORTH DAKOTA

* UNTIL 1100 PM CDT

* AT 1030 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 3 MILES SOUTH
  KINDRED OR 20 MILES SOUTHWEST OF FARGO. THE STORM WAS MOVING
  NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WILD RICE AY 1050 PM
  0XBOW BY 1050 PM

DURING THUNDERSTORMS YOU SHOULD MOVE INSIDE A STRONG BUILDING.
DO NOT STAND BY WINDOWS.  DO NOT USE TELEPHONES OR ELECTRICAL
APPLIANCES.

KENNEDY

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Forks, ND wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 25, 8:10 PM CDT, 2 hours 20 minutes earlier.

Area forecast discussion, Sep 25, 8:10 PM CDT, 2 hours 20 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
810 PM CDT FRI SEP 25 1998

FCST CHALLENGE TONIGHT...SHOWERS.

21Z RUC AND EARLIER MODELS SHOWED WIDESPREAD 850MB WARM ADVECTION
TAKING PLACE THIS EVENING.  850 THETA-E ADVECTION ALSO
IMPRESSIVE...WITH THIS AREA SLIDING NORTHEAST INTO MN OVERNIGHT.
CURRENT 88D SHOWS MAIN BAND OF PCPN FROM SOUTH OF DVL EAST TO NR BJI...
MOVING NORTHEAST AT ABOUT 30KT.  SOME LIGHTNING STRIKES FROM TIME TO
TIME AS MID LEVEL LAPSE RATES ARE MARGINALLY SUPORTIVE OF THUNDER.

12Z MODELS DID NOT INDICATE CURRENT PCPN PATTERN WELL...BUT SHOWED
GENERAL FLOW AND 850 WARM ADVECTION OK.

BASED ON CURRENT SATELLITE AND LATEST RUC EXPECT SHOWERS TO CONTINUE TO
MOVE NORTHEAST AND GRADUALLY END OVERNIGHT.

WILL NEED TO UPDATE DVL ZONE AS NO PCPN IS CURRENTLY IN FCST.  88D
SHOWS PCPN KNOCKING ON BENSON COUNTY DOORSTEP SO WILL UPDATE TO ADD
SCAT SHRA/TSRA TONIGHT.  WILL HAVE SCT SHRA/TSRA REST OF CWFA TONIGHT.

WILL CHECK OVER LOW TEMP FCST...BUT ATTM THEY APPEAR OK.

WILL SEND UPDATE OUT BY 820 PM.

RIDDLE

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 25, 9:27 PM CDTSevere Thunderstorm WarningFGFRansom33 min
Sep 25, 10:03 PM CDTSevere Thunderstorm WarningFGFRansom32 min
Sep 25, 10:18 PM CDTSevere Thunderstorm WarningFGFRichland32 min
Sep 25, 10:37 PM CDTTornado WarningFGFRichland33 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 1998Every severe thunderstorm warning in 1998

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.